This invention relates to apparatus for the fitness and sports training of wheelchair users, and more particularly to three-wheel racer wheelchair support apparatus for permitting more effective workouts and better utilization of the trainer's computerized features.
Wheelchairs are commonly used by physically disabled persons both for everyday transportation and for participating in sports activities such as road racing, basketball and tennis. One type of wheelchair, known as a "racer" wheelchair and used for competition road racing, includes a frame to which two large rear wheels are rotatably mounted for being hand-driven by the user, one on each side of the frame for supporting the frame along with one generally smaller front wheel. An example of such a three-wheel racer wheelchair is shown in U.S. Pat. No. 5,333,894 to Mayes, which patent is incorporated herein by this reference.
Physiological training of the racer wheelchair user, for rehabilitation, fitness and proficiency in road racing, has been implemented in the past by various exerciser or trainer devices. In one type of trainer, a pair of rollers are rotatably mounted in a frame with their rotational axes parallel to each other and spaced to cradle the wheelchair's two rear drive wheels. The wheelchair is driven up a ramp, and the rear wheels are rolled into the roller cradle and hand driven by the wheelchair user to drive the rollers in which the wheels are cradled. It has been experienced that the contact of the rubber tires at the periphery of the wheelchair's drive wheels, when drivably cradled between the two rollers, produces undesired drag, "scrubbing" the rubber from the tires while often providing an audible squeal. Scrubbing is thought to be caused by the circumstance that the wheelchair's drive wheels are generally set closer together at the top than at the bottom, a condition referred to as "camber". Scrubbing may be further increased if the rear drive wheels are additionally set so that they are closer together at the front than at the back (or closer together at the back than at the front), a condition known as "toe".
Trainers for three-wheel racer wheelchairs are known where scrubbing is substantially reduced. One such trainer includes a single roller for being driven by the racer wheelchair's two drive wheels, with the front wheel supported in place such that the centers of each of the drive wheels are directly vertically above the roller rotational axis. Another such prior art trainer, developed by the present inventors, utilizes two rollers of different diameters with their rotational axes parallel to one another and with the crest of each roller in the same horizontal plane. When used with a racer wheelchair, the wheelchair may be positioned such that its front wheel is supported in place with the centers of its drive wheels directly vertically above one or the other of the roller axes for driving the roller which is contacted by the drive wheels.
A second source of drag, however, is produced by the weight of the racer wheelchair and its user upon the driven roller. Although such drag may be acceptable for purposes of a workout, it hinders a computerized trainer's effectiveness in utilizing certain features such as permitting the racer wheelchair user to "race" against best racing times at various actual race tracks present in the computerized trainer's database. Also, in driving a racer wheelchair, it is usual for the user to hit the drive wheel hand rails downwardly with substantial force, which can break the tire's valve stem if the stem is in the vicinity of the roller when the hand rails are hit.